Correct option is A
The correct answer is depleted in oxygen.
· Boiling creates bubbles that contain dissolved oxygen.
· When boiling the water, the dissolved oxygen present in the water decreases.
· An increase in temperature results in decreased levels of dissolved oxygen in the water.
· This can harm aquatic animals such as fish, amphibians and other aquatic organisms.
· Cooling the water to room temperature speeds up the process of oxygen dissolution in the water.
· However, for higher dissolved oxygen level in the aquarium water more mixing and agitation are required.
· That's why it's important to have an aeration device, a bubbler, in the aquarium.